Tanks, in particular metal tanks for fuel such as gasoline in automotive use, are susceptible to rust, deterioration, physical damage, and especially failure at the seams or flanges where formed portions of the tank are joined together. The welds, brazings, or other fusions of such seams are the locations of a majority of tank failures.
Historically, leaky tanks are removed from the vehicle, purged of fuel and fumes, then welded or brazed or otherwise plugged where necessary; a procedure which frequently costs hundreds of dollars.
Lately it has become practice to cover the entire tank, irrespective of the location of a failure, with a combination of inorganic fibers and resin. In this process, the combination is generally applied to the cleaned tank exterior by covering it with a self-curing resin in somewhat liquid form; then applying, for example, glass fiber in the form of a mat of random fibers; or as a woven glass fabric; or indeed as loose roving; then applying additional resin, if necessary. Alternatively, the fiber material may be applied first, followed by a thorough wetting with resin. Again, as a third method, a previously resin-wetted fiber mat may be applied.
In any of the application methods above, the combination is conformed to the tank by splicing and/or cutting and fitting at corners. Pressing and/or rolling complete the laying down of the combination. It will be understood that the layers of the combination may be applied to cover especially weak, deteriorated or extensive areas.
The resin may be poured, brushed or sprayed on. In order to promote the curing, or hardening, of the resin, and thus create a finished product ready for use, a catalyst and a suitable accelerator are generally mixed into the liquid resin to establish a mixture having a viscosity preferred for handling, and to arrive at a desirable curing time.
An example of repairs such as generally described above may be seen in the 1960 U.S. Pat. No. 2,924,546 to Shaw, wherein a repair is disclosed as a tape combination applied to damaged pipe. In the 1961 U.S. Pat. No. 3,622,371 to Sparks, there is disclosed coverings comprised of a thermosetting epoxy resin, a curing agent and glass fibers, adhered to a partially sandblasted surface.
Neither of the above patents addresses the problems encountered in adequately covering the most difficult-to-seal portion of a tank; namely, the area represented by the outwardly extending metal flanges where the tank half shells are joined.
In the 1987 U.S. Pat. No. 4,662,959, Morgan proposes to close the area by trimming each of the resin-inpregnated glass fiber mats at the edge of the flange and then manually pinching together the open ends of the mats.
Thus, neither the Shaw U.S. Pat. No. 2,249,546 nor the Sparks U.S. Pat. No. 3,622,371 solves any edge sealing problem, while the Morgan U.S. Pat. No. 4,662,959 neither envisions nor suggests a method which creates a continuous fiber-resin joint without open ends, including an incorporated channel-clamping member.